Modern ideas about endometrial disorders with habitual miscarriage

The cause of 75% of all implantation failures is impaired endometrial receptivity. Most of the implantation window markers studied are regulated by estradiol and progestrone. Steroid hormones are involved in the binding of molecular makers to specific nuclear receptors and any disturbance in steroid receptor expression can lead to impaired endometrial morphofunctional properties and receptivity. There are three levels of receptivity: genetic, proteomic, and morphological. According to genetic studies, during the implantation window period, there is a 10-fold increase in the expression of about 395 genes in parallel with a decrease in the expression of other 186 genes, various proteases, cell adhesion molecules and matrix proteins. Proteomic markers that affect endometrial receptivity include various growth factors, cytokines, cell adhesion molecules, and integrins. One of the main markers of the morphological level of receptivity is the pinopodia. Over the past 20 years, a large number of molecular markers of endometrial receptivity have been studied and the understanding of implantation mechanisms has expanded. But, despite this, no ideal marker for the assessment of endometrial receptivity in impaired fertility has been found. For the most accurate and effective diagnosis and to reduce the incidence of early reproductive loss, it is necessary to investigate all three levels of endometrial receptivity.